Field of the Invention:
The invention relates to an apparatus for drying a hearing aid, and also a hearing aid, a system consisting of a charging device and a hearing aid and a method for drying a hearing aid according to the invention.
Hearing aids are portable hearing appliances which provide care for persons with hearing impairment. In order to meet the numerous individual needs, different types of hearing aid such as behind-the-ear hearing aids, hearing aids with an external earpiece (RIC: receiver in the canal) and in-the-ear hearing aids, e.g. concha hearing aids or canal hearing aids (ITE, CIC) also are provided. The hearing aids listed by way of example are worn on the outer ear or in the auditory canal. In addition, however, bone-conduction hearing aids, implantable or vibrotactile hearing aids are also available on the market. The damaged hearing is stimulated either mechanically or electrically.
Hearing aids have openings to allow sound to pass from the earpiece of the hearing aid to the ear and into the hearing aid to the microphones. These openings may also be covered with membranes, but, in order to enable a pressure equalization, it is necessary for at least gases and therefore also water vapor to be able to penetrate the hearing aid. Due to the better acoustic characteristics, it may also be desirable to dispense with films of this type.
Due to a temperature drop in the hearing aid, for example between parts of a housing which is in contact with the skin of the wearer and is heated in this way and other areas of the housing which are cooled by the ambient air, condensation occurs inside the hearing aid in the cooler areas of the hearing aid. This effect can be observed particularly in the case of ITE hearing aids, which are exposed to a moist atmosphere at body temperature in the auditory canal, whereas external parts are significantly colder at low air temperature.
In order to ensure the functional capability of the hearing aid and prevent corrosion in the long term, it is necessary to dry the hearing aid internally also. For this purpose, it is known for the hearing aid to be heated in a drying apparatus from outside over a certain time until the moisture on the inside evaporates and diffuses from the housing.
However, the process takes a lengthy time and, as a result, the moisture may initially be deposited from the heated housing onto cooler internal components.
In EP 2 493 215 A1, an arrangement is described for drying a hearing aid, with a heating unit which heats and thereby dries the hearing aid from outside. The drying process takes place depending on a measurement of a moisture sensor.
In EP 2 037 701 A1, a hearing aid with an electric heating device is described. In one design, a receiver coil which is also used for inductive energy transfer serves as a heating device.